Shelf Design

 

There has been quite a bit of discussion on The Leatherwall recently about arrowshelf/sight window construction and modification. I thought that this might be an appropriate time to look at this subject in depth. The design of the shelf can greatly impact arrowflight, due to the fact that when an arrow is released any contact with the bow riser will create drag. Good shelf/sightwindow design will help make a bow capable of shooting a wider range of arrows and will be more forgiving of a less than perfect release.

There are 3 basic types of shelf designs; flat, radiused and ridged. The diagrams below picture these 3 variations.

The radiused shelf is the most common on both longbows and recurves. As illustrated in the picture, the radius reduces the amount of arrow-to-bow contact.

The flat shelf is also relatively common, especially on some older styled recurves. When a bow has this style of shelf it is necessary to use an elevated rest to get the fletching clearance necessary for good arrow flight. One trick that has been used in this situation is to place a thin narrow strip of leather under a rug rest and continue it up the sightwindow under the strike plate. This will allow more clearance and therefore help with flight.

The ridged shape, I believe, is the design that offers the best clearance, since the arrow-to-bow contact is at its absolute minimum.

Other characteristics of good shelf design are beveled edges and narrow sloping shelves. Both of these factors limit unnecessary contact. Figure 2 illustrates both of these features.